A woman whose blood-alcohol level was over four times the legal limit during a traffic stop is back on the road due to an incredibly rare medical diagnosis.

The 35-year-old woman from New York (whose identity has not been released due to medical confidentiality laws) was stopped near Buffalo in October of 2014 and charged with driving while intoxicated after a Breathalyzer test showed her blood-alcohol content to be 0.33%.

The woman swore she hadn’t had more than three drinks in the six hours before she was stopped, so her lawyer consulted professor Barbara Cordell of Panola College in Carthage, TX. Cordell is in expert on "auto-brewery syndrome” – a rare condition in which high levels of yeast in the intestines causes a patient’s body to ferment food high in carbohydrates into alcohol.

After months of tests and monitoring, Cordell was able to diagnose the woman with the condition, prompting a judge to dismiss the charges against her this week.

Assistant Erie County District Attorney Christopher Belling told the Toronto Sun the case is being reviewed and his office doesn't comment on open cases.

According to The Sun, auto-brewery syndrome was fist documented in Japan in the 1970's and is being used as a legal defense more frequently as it becomes more well known.